Discovery! 18,000 dinosaur tracks discovered along ancient Bolivian coastline!

 Wow! 18,000 dinosaur footprints were discovered in Bolivia recently! Think of how long it took to count them, then analyze them!

(image: With the discovery, Carreras Pampa in Bolivia has become one of the premier dinosaur track sites in the world. (Image credit: Raúl Esperante)

18,000 dinosaur tracks discovered along ancient Bolivian coastline — and they set a new record 

 By Sascha Pare, Science News, Dec. 4, 2025

Researchers have counted 16,600 fossilized dinosaur footprints and 1,378 swim tracks at a site in Bolivia that showcase a variety of behaviors and different theropods from the Cretaceous period.

The tracksite sits along what was once an ancient coastline, with ripple marks extending alongside the footprints and other imprints in a northwest-southeast direction, according to a new study. Most of the tracks belong to bipedal, three-toed dinosaurs known as theropods that lived at the end of the Cretaceous period (145 million to 66 million years ago), but many bird tracks are also preserved, the scientists noted in the paper, which was published Wednesday (Dec. 3) in the journal PLOS One.

"This is the highest number of dinosaur footprints ever found for a single tracksite thus far," study co-author Jeremy McLarty, a paleontologist and associate professor at the Southwestern Adventist University in Texas, told Live Science in an email. "In addition to preserving the most dinosaur tracks worldwide, it also preserves the highest number of swim trackways in the world."

In total, McLarty and his colleagues counted 16,600 theropod footprints and 1,378 swim tracks. These were found in Bolivia's Carreras Pampa tracksite, which was already known but hadn't been properly studied or documented.

Carreras Pampa extends across 80,570 square feet (7,485 square meters) in Torotoro National Park. The initial work involved sweeping debris off the dinosaur imprints with brooms, clearing the tracksite of rocks and removing sediment in places where additional tracks were likely to be found.

(Image credit: Total Dino.com) 

The team discovered a huge variety of footprint shapes and sizes, indicating that many types of theropod dinosaurs roamed along the ancient coastline. Several tracks had footprints shorter than 4 inches (10 centimeters), which is rare in the fossil record, according to the study. It's unclear if these footprints were made by small theropod species such as Coelophysis or by juveniles of larger species, the researchers wrote.

What is Coelophysis? Coelophysis was a primitive theropod dinosaur. Usually growing to length of about 2 metres (6.6 feet), it was very light, weighing only about 18–23 kg (40–50 pounds), and had a long, slender neck, tail, and hind legs. The head was long and narrow, and the jaws were equipped with many sharp teeth.

The largest footprints were more than 12 inches (30 cm) long, and the team thinks these may have been made by mid-size theropod dinosaurs such as Dilophosaurus or Allosaurus. Large theropods such as Tyrannosaurus rex and Giganotosaurus typically leave 16-inch-long (40 cm) footprints, the researchers noted.